Many types of chemical and physical apparatus resuire connection between a metallic and a non-metallic, typically glass or ceramic element. These two elements have substantially different thermal coefficients of expansion, and under thermal loading, the flange connections have the tendency to cause difficulties. For example, upon increase in temperature, the substantially different thermal coefficients of expansion of glass or ceramic and of metal have the tendency to cause fracture of the glass or ceramic element which is essentially brittle. The fracture, or failure of the flange connection, is due to the increased tension in the glass or ceramic material.